Issue 4191 - Fix typo in shadowRoot descriptor

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 456 matching lines @@
     // Stop the website from messing with our shadowRoot
     if ("shadowRoot" in Element.prototype)
     {
       runInDocument(document, function()
       {
         var ourShadowRoot = document.documentElement.shadowRoot;
         var desc = Object.getOwnPropertyDescriptor(Element.prototype, "shadowRoot");
         var shadowRoot = Function.prototype.call.bind(desc.get);
 
         Object.defineProperty(Element.prototype, "shadowRoot", {
-          conifgurable: true, enumerable: true, get: function()
+          configurable: true, enumerable: true, get: function()
           {
             var shadow = shadowRoot(this);
             return shadow == ourShadowRoot ? null : shadow;
           }
         });
       }, null);
     }
   }
 
   function addElemHideSelectors(selectors)
@@ skipping 122 matching lines @@
   }, true);
 
   return updateStylesheet;
 }
 
 if (document instanceof HTMLDocument)
 {
   checkSitekey();
   window.updateStylesheet = init(document);
 }